On Sat, 30 Oct 2004 01:27:53 -0400, Gene Heskett
<gene.heskett AT verizon DOT net> wrote:
> To defeat that, and make an uncompressed tape out of a tape that has
> been written with the compression on, will require that the correct
> software command be issued (in my case it wasn't a 0, but an 'off'
> command issued by mt), and then sufficient data written to force the
> drive to flush its buffers, at which point the compression flag on
> the tape will be reset.  This is commonly 4 to 10 megs of garbage to
> force this.  I had written a script that would rewind the tape, read
> out the tape label to a scratch file with dd, rewind it again, issue
> those compression off commands, then rewrite the label block just
> read with dd, followed by another 5 megs worth of "dd if=/dev/zero
> bs=32768 count=160 of=/dev/nst0", and then rewind the tape again.

Thanks for the tips, Gene.  Between this information, and the info
Paul pointed me to, I should be all set.

Thanks-
Erik